Top Ten Software Defined Storage Tips, Gotchas and Cautions

Software Defined Storage (SDS) is a somewhat clunky term that some of us hoped might disappear by now. But it has hung in there and gathered momentum in recent months.

That said, buyer beware! One IT pro’s SDS is another IT pro’s marketing hype. Here are ten important tips, gotchas and points to consider for anyone considering SDS purchases.

1. Find Out What You Are Buying

Scott Sinclair, Storage Analyst at Enterprise Strategy Group, warns users that there are many different vendor takes on what SDS is and how it should best be provided. A common theme for a variety of SDS solutions, though, is hardware abstraction. But that can mean different things. For some implementations, it is the ability to virtualize multiple external storage arrays as a single pool, while for others it includes the addition of commodity server hardware.

“Be aware that there are many solutions out there leveraging the SDS moniker,” said Sinclair. “Make sure to talk to multiple partners to understand what is unique to their implementation and how it impacts your bottom line.”

2. Commodity Hardware May Not Mean Cheaper

For years, storage managers have complained about the high cost of proprietary hardware. So it’s understandable that the commodity hardware-based storage argument resonates with them as a way to lower costs and avoid vendor lock in. But with SDS, commodity hardware does not necessarily mean cheaper.

“SDS that leverages commodity hardware can provide storage at a lower cost point, but you end up having to acquire new infrastructure upfront,” said Sinclair. “Alternatives that virtualize multiple storage arrays can reduce upfront costs by leveraging existing storage hardware that is already deployed on site.”

3. Integration Headaches

Another cost gotcha is integration, added Sinclair. In some cases, the SDS vendor validates the commodity hardware but in others it is the IT organization that is responsible for integration. If your organization is not equipped do your own hardware integration from a personnel or budgetary standpoint, you could select the wrong vendor by failing to determine how the commodity hardware is to be implemented at your location.

4. Verify Hardware Compatibility

While in theory SDS software stacks can run on any x86 general purpose server, in reality most SDS offerings have a strict hardware compatibility list (HCL). Most new hardware, whether it’s new type of drives, spinning or flash, or newer HBAs, just don’t work automatically with the SDS software, said Chandra Mukhyala, SSD Solutions Manager, Dell Storage. Problems can range from the solution simply not recognizing the new hardware to intermittent disk failures and poor visibility into hardware issues.

“Users should approach SDS cautiously if they are trying to put together a SDS solution on their own,” said Mukhyala.

5. Avoid Appliances

It is understandable that some in the SDS camp would warn users to avoid appliances. After all, SDS is all about freeing yourself from hardware. So why the appliance?

“There’s either a significant requirement that ties the product to specific hardware, where you’re back in classic appliance lock-in,” said Leo Leung, Vice President of Corporate Marketing, Scality, “or a business model that dictates hardware sales, meaning you’re better off with a large incumbent that has the actual buying power to get you sustainable commodity savings versus a tiny SDS vendor that is margin-constrained.”

6. Watch That App Workload A big point that can be missed in the storage world is that the storage itself exists to facilitate data that is accessed by applications. So a common mistake is not to pay enough attention to an application’s workload, said Mukhyala.

“There are a variety of SDS solutions in the market that are best suited for specific workloads,” said Mukhyala. “It is important to match the SDS solution with one’s particular workload to get the best price-performance.”

7. All of the Above

As mentioned earlier, there are several different methods of implementing SDS. The general concept enables users to package software data services in various forms – as a dedicated array, as a unique piece of software on a server, as a hyper-converged platform or natively built into a cloud. There is no one approach that is right for all use cases. It depends on the applications, the existing environment, internal capabilities and the overall purpose of SDS within that business.

“Some SDS solutions can introduce an additional layer of complexity,” said Sinclair.

That complexity, he reminded users, can extend to the supply chain. Some approaches to SDS transforms the storage environment from one source supplying both the hardware and software, to a possible mixed solution with one partner providing the software and potentially multiple partners supplying the hardware. While some SDS vendors have taken steps to make fault isolation and issue resolution simple, there can be an increased level of complexity if a failure occurs simply from having multiple partners in the solution, added Sinclair.

9. Be Self-Absorbed

Vendors will try to atttibute all kinds of wonders to the latest software defined architectures. So how do you slice through the noise and pick what will do you the most good? Greg Schulz, an analyst at StorageIO Group, has a good suggestion – be self-absorbed.

“Look for solutions that enable you to protect your existing investment in servers, storage, networking, management tools and skillset experiences as opposed to forcing you to rip and replace,” said Schulz. “The SDS solution should complement your environment, not compete with it.”